Warp knitting machine



May 11, 1948. R. F. ESHLEMAN WARP KNITTING MACHINE 2 Sheets-Sheet 1Original Filed March 27, 1945 May 11, 1948. ESHLEMAN 2,441,189

WARP KNITTING MACHINE Original Filed March 27, 1945 Z-Sheets-Sheet 2 INEN TOR. @MxmM Patented May 11, 1948 WARP KNITTING. MACHINE Richard F.EshlemamWest Chester, Pa., assignor to American Viscose Corporation,Wilmington, DeL, a corporation of Delaware Y Continuation of applicationSerial No. 585,052, March 27, 1945. This application September 19, 1946,Serial No. 697,987. In Great Britain December 5, 1945 This inventionrelates to warp or tricot knitting machinery and is particularlyconcerned with arrangements for feeding the yarns from the Warp beams orsectional warp beams under controlled tension to the needles of themachine. This is a continuation of an application now abandoned, filedMarch 27, 1945, Serial No. 585,052.

In the conventional warp knitting machine, the threads are drawn fromthe warp beam by pulling action initiated by the needles themselves. Thewarp beam is associated with a suitable brake or equivalent mechanismwhereby it is released for rotation whenever the needles or otherknittin elements, such as the guides, call for thread, and whereby it issecured against rotation in the intervening periods. This arrangementhas various disadvantages, the most important of which being thelimitation of the speed at which the machine may operate. Since thefeeding of thread is dependent upon the release of the brake in responseto increase in tension of the yarns, it is apparent that the threadfeeding tends to lag behind the knitting element or needle requirements.This lagging effect gives rise to a wide variation in the tension whichbecomes most pronounced at high speed and definitely limits the maximumspeed at which satisfactory fabrication can be effected. There have beenvarious suggestions to provide for positive feeding of the yarnindependently of the drawing action of the needles but none of thesuggested arrangements has been found to be practical. For example, ithas heretofore been proposed to intermittently drive the yarn supplybeams independently of the needles but such intermittent motions are notadaptable to high speeds.

In accordance with the present invention, the supply beams for a givenwarp are rotated continuously at the same constant peripheral (yarnperiphery) speed and there is provided between the feeding means and theknitting elements a positively driven means for varying the path of theyarns in timed relation to the knitting cycle so that when the knittingelements draw a thread at a greater linear speed than the delivery speedof the feeding means, the length of the yarn path is decreasedproportionately to make up the additional length of yarn needed by theelements and when the requirements of the elements are less than therate of feed from the supply means, the. yarn will take a longer path,thereby compensating for the discrepancy between the constant feedingrate and the varying requirements during the knitting cycle. Thispositively driven means may be associated with, or entirely independent16 Claims. (Cl. 6.686)

of, the tensioning devices, such as the conventional tension bars andmay advantageously take its movement from the cam shaft of the knittingmachine which controls the knitting cycle.

In the drawing, illustrative of the invention- Figure 1 is a somewhatdiagrammatic end view (partially in cross-section) of a machine embody-fing the present invention,

Figure 2 is a back elevational view of the embodiment of Figure 1,

Figure 3 is an end view of a modification,

Figure 4 is an end view of another modification, and l I Figures 5 to 8illustrate the knitting cycle.

For the purposes of illustration, the invention is shown in connectionwith a two-warp machine though it may be used with a single warp, atriple warp or higher warp machine. All of such machines comprise theguides G and G the needles N, the sinkers S, all of which constitutethe'insides or knitting elements-0f the machine, and the presser bar P.The needles, guides, presser and sinkers are mounted on correspondingbars which partake of motions controlled by various cams disposed on thecam shaft of the machine driven by a motor in the conventional manner.

In a warp knitting machine of the-typeshown in Figures 1 and 2, theknitting cycle comprises generally the following sequence of steps takenby the knitting elements referring -to the rela tionships shown inFigure 5- as the starting position. In Figure 5, the guides G and G arein their forward position in front of the needles N which are in theirlapping position of intermediate height with their shanks extendingthrough the most recently formed loops of the fabric F. As shown inFigure 6, the guides-move back of the needles and then move laterally tolap their threads around the needles. Then the guides return to theirforward positions to complete the loops around the needles at which timethe needles rise to their uppermost position to place the new loopsunder their beards. As the needles start downwardly, the presser bar Pmoves forward to close the beards of the needles over these loops andthesinkers S move back somewhat so that the relative positions of Figure 7are reached. Thenthe needles continue to'move downwardly toidraw ,the'new. loops within the closed beards through the previously formed loops.

this position, the needles rise-to lapping position,

as shown in Figure 5.

It will thus be seen that there arecer'tain in tervals of time when theneedles require thread and others when they do not. The chief demand forthread is during the time that the new loops are drawn downwardly by theneedles through the old loops. Immediately after this period 'of theknitting cycle, until the needles have risen again to their lappingposition there is no demand for thread whatsoever. When the guides lapthe threads about the needles, there is some demand by the guides forthread which may be of less, comparable, or greater magnitude than thedemand when the new loops are drawn through the old loops depending uponthe number of needles about which the loops are formed.

Referring particularly to the embodiment of Figures 1 and 2, both theupper and lower tiers of sectional warp beams 2 for supplying front andback warps respectively are mounted for free rotation and are supportedupon pairs of parallel rolls 3 which are driven in synchronism. Therolls-may have cork or rubber surfacesto ive good ffhctional drivingcontact with'the periphera? windings of yarn on the beams withoutabrasion thereof; As shown, the pairs of rolls are driven by sprocketand chain connections wan the common shafts 4 extending the length ofthe machine. The common driving shaft 4 for each warp supply isconnected to that of each of the others, such as by the 5 and sprocketconnection shown, the sizes of the sprockets 6 and 1 being predeterminedin. retaticn to the speed or'take-up to produce definite ratio of yarnspeed in the several warps. This ratio may be varied widely dependingupon the pattern of fabric desired. For driving the common-shafted achain 8 and sprocket connection with tnemctor a may be used and itisadvantageous to provide an infinitely variable speed reducer -IFbetween' the motor 9 and the sprocket for driving chain 8 in order toobtain any desired feeding speed. The motor 9 for driving theyarn-feeding rolls may be the same as that for driving the cam shaft ofthe machine, as shown, or separate motors may be used if desired. As theyarns proceed from each warp supply, they proceed about the tension barsH and thence to thegoides G" and and needles N. The tension bars maybecarried in conventional fashion upon pivotally mounted levers 1 2provided at each end thereof, each lever having an arm is agafnstwhicha, spring i exerts a pressure in opposition to-the'tendency of anysudden development of tension in the yarns to move the tension barsdownwardly.

The cam shaft [5 is provided with the conventionai' cams and the machinehas the conventional followers for transmitting the motion to thevarious knittingelementssuch as the needles, guides and sinkers as wellas to the pres'ser bfar associated therewith. These various cams and camfol-lowers may be conventional and hence are not shown. In accordancewith the present invention, however; the cam shaft is also provided withcams [6 which are associated with the followers IT comprising thepivoted levers H? and the rods [9 connected thereto. The rodsareconnectedby a pin and slot joint to the levers i2 carryingthc tensionbars. A separate cam 18 and cam follower system H is rovided for eachwarp tension bar I I. These cams l6 positively'vary'the paths takenbythe warp sheet withiwhich they are associated and while their shapemayvary' widely depending upon the particular fabric pattern desired,they are functionally reiated tothe cams of the knitting elements andparticularly the needles so that the path taken by the yarns in the warpsheet is decreased when there is a demand for yarn by the needles and/orguides in excess of the normal rate of supply by the respective warpsupply beams and increases thepath when the reverse relationship betweenthe supply rate and the knitting requirement occurs during the knittingcycle. Preferably, the cams are of the split variety which are readilyremovable from the cam shaft without dismantling the machines so that.they may be replaced with cams of other patterns to provide other fabricpatterns.

The arrangement of the embodiment of Figures 1. and 2 is such that thereis no interference with the spring-tensioning action of the tension barsand there isa variation in the yarn path imparted to the yarns of eachwarp, superimposed on the normal variation resulting from changes intension, by the positive movement of the tension bars imparted by thecam shaft in timed relation to the knitting cycle. The connection of therods [9 with the levers I 2 supporting the tension bars comprises a pinand. slot connection so that even when the tension bar supporting leversare moved positively they are still responsive to any increase intension imparted to the yarn regardless of the cause thereof.

Figure 3 shows a modification in which the sectional beams 2 aresupported in a guideway fit within which they are vertically movable andare carried. with their yarns in direct contact with the driving rolls3a directly therebeneath, a single roll being used in each case insteadof the two rolls of the embodiment of Figures 1 and 2. The cam shaft l5drives a chain 22 which in turn drives a rotatable rod 23 having aneccentric yarn-engaging surface extending the length of the warp sheetso that as this eccentric rod rotates, the paths of the yarns in thewarp sheet are increased and decreased at predetermined intervals, thesprockets 24 being of the same size so that the variation in the yarnpath occurs in timed relation with the knitting cycle and has the sameperiod as such cycle. Preferably, the eccentric 23 is so rotated thatits surface moves in the same direction as that of the yarn incontact-therewith.

As: shown in- Figure l, the. supply beams 2 (only one being shown) maybe driven positively by means of one or more supporting belts 25 carriedand driven by rollers 26, a guideway 2| (similar to that of Figure 3)being provided at each end of the beam to allow it vertical movement inresponse to change of diameter.

While the embodiment of Figures 1 and 2 shows two warps and those ofFigures 3 and 4 show one "warp, it is to be understood that theinvention is applicable to machines using any number of warps. In allcases, all tension bars. are positively moved in timed relation to theknitting cycle. While in special cases, all the tension bars may taketheir movement from a single cam and follower system, in order to obtainthe widest variety of fabric patterns, it is preferable to use aseparate cam and follower system for each tension bar.

The present invention makes it possible to uniformly feed the yarnsunder controlled tension to the knitting elements. Whereas heretoforethe fabric pattern or quality depended a great deal upon the adjustmentof the tension bars and the toughness of the springs associatedtherewith, and such adjustments were not readily duplicable, the presentinvention makes it possible to determine the quality of fabric beforeany cloth is knitted and to duplicate a given quality of fabric simplyby setting the take-up speed, at least one of the warp speeds, and theratio between the warp speeds. 'I'hemovements of the various machineelements are continuous so that the present invention is adaptable tothose machines in which high speeds are desired. In addition, thepositive control of the yarn path in timed relation with the knittingcycle, Without relying on the drawing action of the needles to vary theyarn path or the speed of the warps, assures smooth operation withoutthe development of sudden increases or decreases in tension.

It is to be understood that changes and variations may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

I claim:

1. In a warp knitting machine, knitting elements comprising guides andneedles, a cam shaft for controlling the knitting cycle of the elements,at least one warp supply beam, means for continuously feeding yarn for apredetermined warp from the supply therefor at a predetermined constantspeed, and means engaging the yarn proceeding from the supply thereofbefore it reaches the guides for varying the length of the path of theyarn from the feeding means to the elements in timed relation to theknitting cycle to substantially compensate for discrepancies between theconstant feeding rate and varying yarn requirements of the elementsduring the knitting cycle.

2. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, at leastone warp supply beam, means for continuously feeding yarn for apredetermined warp from the supply therefor at a predetermined constantspeed, and positively driven means for varying the length of the path ofthe yarn from the feeding means to th elements in timed relation to theknitting cycle to substantially compensate for discrepancies between theconstant feeding rate and varying yarn requirements of the elementsduring the knitting cycle.

3. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, at leastone warp supply beam, means for continu-- ously feeding yarn for apredetermined warp from the supply therefor at a predetermined constantspeed, spring means for tensioning the yarn between the feeding meansand th needles, and positively driven means for varying the length ofthe path of the yarn from the feeding means to the elements in timedrelation to the knitting cycle to substantially compensate fordiscrepancies between the constant feeding rate and varying yarnrequirements of the elements during the knitting cycle.

4. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, at leastone warp supply beam, means for continuously feeding yarn for ,apredetermined warp from the supply therefor at a predeterminedsubstantially constant speed, spring means for tensioning the yarnbetween the feeding means and the needles, and positively driven meansassociated with the tension means for varying the length of the path ofthe yarn from the feeding means to the elements in timed relation to theknitting cycle to substantially compensate for discrepancies between theconstant feeding rate and varying yarn requirements of the elementsduring the knitting cycle, the positively driven means being arranged toimpose its effects on the tension means in opposition to the springmeans.

' 5. In a Warp knitting machine, knitting elements comprising needles, acamshaft for controlling the knitting cycle of the elements, at leastone warp supply beam, means for continuously feeding yarn fora'predetermined warp from the supply therefor at a predeterminedsubstantially constant speed, and means driven by the cam shaft forvarying the length of the path of the yarn from the feeding means to theelements in timed relation to the knitting cycle to compensate fordiscrepancies between the constant feeding rate and the varying yarnrequirements of the elements during the knitting cycle.

' 6. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, at leastone driven roll, a warp supply beam adapted to rest with its peripheralwindings on said roll so as to be driven thereby, means for driving saidroll at constant speed to feed yarn therefrom, and means driven by thecam shaft for varying the length of the path of the yarn from thefeeding means to the elements in timed relation to the knitting cycle tocompensate for discrepancies between the constant feeding rateandvarying yarn requirements of the elements during the knitting cycle.

'7. In a warp knitting machine, knitting elements comprising needles, acam shaft for con trolling the knitting cycle of the elementsat leastone Warp supply beam, means for continuously feeding yarn fora-predetermined warp from the supply therefor at a predeterminedsubstantially constant speed, a tension bar for tensioning the yarnbetween the feeding means and the needles, and means driven by the camshaft and connected to the tension bar for moving said tension bar intimed relation to the knitting cycle to substantially compensate fordiscrepancies between the constant feeding rate and the varying yarnrequirements of the elements during the knitting cycle. 1 1

8. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, at leastone warp supply beam, means for continuously feeding yarn for apredetermined warp from the supply therefor at a predeterminedsubstantially constant speed, a resiliently mounted tension bar fortensioning the yarn between the feeding means and theneedles, suchtension bar being connected to and driven by the cam shaft in timedrelation to the knitting cycle to substantially compensate for thediscrepancies between the constant feeding rate and the 'varying' yarnrequirements of the elements during the knitting cycle.

9. In a warp knitting machine, knitting elements comprising needles, acam shaft for conv trollingthe knitting cycle of the elements, aplurality of supply beams for feedingyarns to a plurality of warps,means for continuously feeding yarn for each warp fromthe supplytherefor at predetermined substantially constant speeds, means foradjusting the ratio between such speeds, and means driven by the camshaft for varying the length of the path of the yarn in each of thewarps from the feeding means to the elements in timed relation to theknitting cycle to substantially compensate for discrepancies between theconstant feeding rate and vary- 7 ing yarn requirements of theelementsduring the: knitting: cycle;

10. In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling; the knitting cycleqofi the elements, a pairof substantially parallel driven rolls, a warp supply beam adapted torest with its peripheral windings, on said roll so as to be driventhereby, means for driving at least one of said rolls at constant speedto supply yarn from the warp supply, and. means driven bythe cam shaftfor varying the lengthof the path of the yarn from the feeding means tothe elements in timed: relation to the, knitting cycle to compensate fordiscrepancies between the constant feeding rate and varying yarnrequirements of the elements during the knitting cycle.- v Y 11. In awarp knitting machine, knitting elements comprising needles, a cam shaftfor controlling the knitting cycle of the elements, a pair ofsubstantially parallel rollers, at least one belt carried about saidrollers, a'warp supply beam adapted to rest with its peripheral windingson the belt or belts so as to be driven thereby, means for driving saidbelt at constant speed to supply yarn from the warp supply, and meansdriven by the cam shaft for varying the length of the path of the yarnfrom the feeding-means to the elee ments in timed relation to theknitting cycle to compensate for discrepancies between the constantfeeding rate and varying yarn requirements of the elements during theknitting cycle.

12. In a warp knitting machine, knitting elements comprising needles, acam shaft for con; trolling the knitting cycle ofthe elements, at leastone driven roll, a warp supply beam adapted to rest with its peripheralwindings on said roll so as to be driven thereby, means for driving saidroll at constant speed to feed yarn from the supply, and a roller drivenby the cam shaft having an eccentric surface engaging the yarnsproceeding from the warp supply beam for varying the length of the pathofthe yarn from the feeding means to the elements in timed relation tothe knitting cycle to compensate for discrepancies between the constantfeeding rate and varying yarn requirements of the elements during theknitting cycle. 1 I

13. In a warp knitting machine, knitting elements comprising guides andneedles, a cam shaft for controlling the knitting cycle of the elements,at least one warp supply beam, means for continuously feeding yarn for apredetermined warp from the supply therefor at a predeterminedsubstantially constant speed, said feeding means comprising at leastoneroll and means for rotating the roll at constant speed, said feedingmeans being arranged to support the beam associated therewith with someof its peripheral windings resting thereon so as to make drivingengagement therewith, and means engaging the yarn proceeding from thesupply thereof before it reaches the guides for varying the length ofthe path of the yarn from'the feeding means to theelements in timedrelation to the knitting cycle to substantially. compensate fordiscrepancies between the constant feeding rate and varying yarnrequirements of the elements during the knitting cycle.

14-. In.;a warp knittingv machine; knitting: ale.- mentscomprising-needles, acam shaft for controlling" the knitting cycle ofthe-elements; at least one warp; s upply beam, -means for contin uouslyfeeding yarn for a predetermined warp from the supply therefor atapredeterminedsube stantially constant speed, said feeding meanscomprising at least one roll and means for rotating the roll at constantspeed, said feeding means being arranged to support the beam associatedtherewith with some of its peripheral windings resting thereon so as tomake driving engagement therewith, and positively driven means forvarying the length of the path of the yarn from the feeding means to theelements in: timed relation to the knitting cycleto substantiallycompensate for discrepancies between the constant feeding rate andvarying yarn requirements of the elements during the knitting cycle.

15. In a warp knitting machine, knitting elements comprising needles,- acam shaft for, controlling the knitting cycle of the elements, at leastone warp supply beam, means for continuously feeding yarn for apredetermined Warp fromthe supply therefor at a predeterminedsubstantially constant speed, said feeding means comprising at least oneroll and means for rotating the roll at constant speed, said feedingmeans being arranged to support the. beamassociated therewith, with someof its peripheral windings resting thereon so as to makedrivingengagement therewith, and means driven by the camshaft for varying thelength of the path of the yarn fro-m the'feeding means to the, elementsin timed relation to the knitting cycle to compensate for discrepanciesbetween the constantfeeding rate and the varying yarn requirements jof.the elements during the knitting cycle.

1'6.'In a warp knitting machine, knitting elements comprising needles, acam shaft for controlling the knitting cycle of the elements, aplurality of supply beams. for feeding yarns to a plurality of warps,means for continuously feeding yarn for each warp from the supplytherefor at predetermined substantially constant speeds, means for,adjusting the ratio between such speeds, each of said feeding meanscomprising at least one roll and means for rotating the roll, atconstant speed, said feeding means being arranged to support the beamassociated therewith with some of its peripheral windings restingthereon so as to make driving engagement therewith, and means driven bythe cam shaft for varying the length of the path of the yarn in each ofthe warps from the feeding means to. the elements in timed relation tothe knitting cycle to substantially compensate for discrepancies betweenthe constant feeding rate and varying yarn requirements of the elementsduring the knitting cycle.

- RICHARD F. ESHLEMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date

